The duo's new song 'The Monster' took over the British boy's in mid-week and it has never looked back.
Despite having a 48 hour disadvantage on the other new singles this week, 'The Monster' rose to the UK top spot, reported The Official Chart Company.
In achieving this feat Rihanna has made chart history thanks to the Eminem track and has joined a very lucrative class of people.
'The Monster' is both artists 8th No.1 UK single and the Barbados born signer now joins The Beatles and Elvis Presley as one of just three acts to top the UK singles chart seven times over seven years.
'The Monster' is Em's first UK No1 since 2006's 'Smack That' featuring Akon. The track is from his latest studio set 'The Marshall Mathers LP 2' which will be released on Tuesday.
The pair's last UK hit was 'Love The Way You Lie' from 2010 which reached No.2. It has since become one of the UK's most successful selling singles ever, with more than 1.15 million copies sold.
New Zealand born Lorde was last week's No.1 with 'Royale' but has now slipped to second position. Coming in 3rd place is Fat Boy Slim's 'Eat Sleep Rave Repeat', the DJ's first top ten in 12 years.
No.4 is the predicted No.1 for this week, which is One Direction's 'Story of my Life'. American rock group OneRepublic, round off the top 5 with their former No.1 'Counting Stars'.
Eminem's 8th studio album 'The Marshall Mathers LP 2' is set to hit the shelves on November 5th 2013.
Rihanna makes chart history
'The Monster' denied One Direction their 4th UK No.1 single